arm/sys/arm_commpage_gettimeofday.c

   1 #include <time.h>
   2 #include <tzfile.h>
   3 #include <sys/time.h>
   4 #include <errno.h>
   5 #include <sys/syscall.h>
   6 #include <unistd.h>
   7 #include <mach/clock_types.h>
   8 #include <mach/mach.h>
   9 #include <mach/mach_time.h>
  10 #include <machine/cpu_capabilities.h>
  11
  12 int __commpage_gettimeofday(struct timeval *);
  13
  14
  15 #define TIME_ADD(rsecs, secs, rfrac, frac, unit)        \
  16 {                                                       \
  17         (rfrac) += (frac);                              \
  18         while ((rfrac) >= (unit)) {                     \
  19                 (rfrac) -= (unit);                      \
  20                 (rsecs) += 1;                           \
  21         }                                               \
  22         (rsecs) += (secs);                              \
  23 }
  24
  25
  26 int __commpage_gettimeofday(struct timeval  *tp) {
  27         commpage_timeofday_data_t *commpage_timeofday_datap;
  28         uint64_t        tbr;
  29         uint64_t        t64;
  30         uint64_t        TimeBase;
  31         uint32_t        TimeStamp_usec;
  32         uint32_t        TimeStamp_sec;
  33         uint32_t        TimeBaseTicks_per_sec;
  34         uint64_t        TimeBase_magic;
  35         uint32_t        TimeBase_add;
  36         uint32_t        TimeBase_shift;
  37         uint32_t        x, q;
  38
  39
  40         commpage_timeofday_datap =  (commpage_timeofday_data_t *)_COMM_PAGE_TIMEOFDAY_DATA;
  41
  42         do {
  43                 TimeBase = commpage_timeofday_datap->TimeBase;
  44                 TimeStamp_sec = commpage_timeofday_datap->TimeStamp_sec;
  45                 TimeStamp_usec = commpage_timeofday_datap->TimeStamp_usec;
  46                 TimeBaseTicks_per_sec = commpage_timeofday_datap->TimeBaseTicks_per_sec;
  47                 TimeBase_magic = commpage_timeofday_datap->TimeBase_magic;
  48                 TimeBase_add = commpage_timeofday_datap->TimeBase_add;
  49                 TimeBase_shift = commpage_timeofday_datap->TimeBase_shift;
  50         } while (TimeBase != commpage_timeofday_datap->TimeBase);
  51
  52         if (TimeBase == 0)
  53                 return(1);
  54
  55         tbr = mach_absolute_time();
  56
  57         t64 = tbr - TimeBase;
  58
  59         if (t64 >= (uint64_t)TimeBaseTicks_per_sec)
  60                 return(1);
  61
  62         x = (uint32_t)t64;
  63         q = ((uint64_t)x * (uint32_t)(TimeBase_magic)) >> 32;
  64         tp->tv_usec = TimeBase_add ? (((x - q) >> 1) + q) >> (TimeBase_shift - 1) : q >> TimeBase_shift;
  65         tp->tv_sec = 0;
  66
  67         TIME_ADD(tp->tv_sec, TimeStamp_sec, tp->tv_usec, TimeStamp_usec, USEC_PER_SEC);
  68
  69         return(0);
  70 }